Method of manufacturing rolling cutters for drilling purposes



Oct. 30, 1945. J. A. ZUBLIN 2,388,108

METHOD OF MANUFACTURING ROLLING CUTTERS FOR DRILLING PURPOSES Filed Nov. 5, 1944 2 Sheets-Sheet l Oct; 30, 1945. zUBLlN 2,388,108

METHOD OF MANUFACTURING ROLLING CUTTERS FOR DRILLING PURPOSES Filed Nov. 3, 1944 2 Sheets-Sheet 2 MINNIE;-

Jm hag 5 Patented Oct. 30, 1945 UNITED, STATES PATENT" OFFICE.

(JUTTERS Eon DEIILING PURPOSES John A. Zubli'n, Los Angeles, Calif. ApplicationzNovemher 3, 1944, serial-No-fifiljiaa 4 Claims. "("Cl. 76-108) This invention relates. to a method. 01 manurolling. cutters for drilling purposes.

Rolling cutters are used particularly in the drilling of wells and are subjected to very great stresses.

In some instances, for example, in the employmentof a turbine-driven gyrating rolling cutter,

such as shown in my U. S. Patent No. 2,336,335,

the inclined shaft which carries the cutter rotates under the action of the turbine at a speed of from 1,000 to 10,000- R. P. M. The cutter is sufllcien-tly out of balance with respect to the turbine axis to set up tremendousvibration in .thewhole turbine, and the drill pipe immediately above the same. In the operation of such turbine-driven gyrating cutterait is desirable to reduce the vibrations to a minimum, and this can best be accomplished by reducing the weight of thegyrating cutter.

Rotating cutters for this use can be machined from a solid block of steel only with great difiicul'ty, particularly where special tooth designs are required. When machined from a solid block of steel, there is, furthermore, a substantial material loss in the cutting 01' the blades and teeth.

It is accordingly the object of the present invention to provide an expeditious method of manufacturing rotating cutters that is both economical of labor and material.

' It is a further object of the invention to provide a method for manufacturing a rotating cutter adapted to mass production methods and capable of producing rotating cutters of light weight possessing maximum tensile and crushing strength.

It a. further and more. specific object. of the invention to provide an expeditious method for manufacturing. rotating cutters from rolled alloy production steel, particularly applicable to the ofsmall-size rotating cutters of intricate design. Further and more detailed objects of the invention will become apparent as the description proceeds, which will be given in connection with the accompanying drawings which illustrate the steps of the method, and in which:

Fig. 1 is a view in side elevation of the machined cutter body;

Fig. 2 is a view in side elevation, partly in section, of a machined bowl employed in forming the blades of the cutter;

Fig. 3 is a cross-sectional view through the blade bowl showing the tooth forming channels therein;

Fig. 4 illustrates the step of cutting segments 30 the from the: blade bowl. to. provide an integral multie bladed web; a

Fig. 5 illustrates the manner in. which short blades are cut from segments removed from the blade bowl;

Fig. 6. is a bottom plan. view showing; the integral multi-bladed web and the; short blades; assembled on the cutter body;

Fig. '7 is a detailed cross-sectional view on: the line 1.'| of Fig. 6 through the finished rotating cutter, particularly illustrating the mannerin which the multi-bladed web and the short blades are. welded to. the cutter'body; and

Fig. 8 illustrates the. adaptation of the method of the. invention. to a bladed cone rotating cutter. In carrying. out. the method: of the present invention, there is first fabricated from rolled alloyed steel by conventional machinerya rotating cutter body indicated at ID in Fig. 1, having ball races II: on its. inner surface, which cutter body is adapted to be. mounted upon a suitable shank. There is next produced what for convenience will. be herein termedv a blade bowl indicated at I2 in. Fig. 2. This blade bowl I2 has an interior configuration. conforming exactly to the exterior configuration of the cutter body I0. The exterior of the blade bowl I2. is first machined as a rotational body to provide a contour representing the desired extremes of the blades for cutter. The blade bowl I2 may then be further machined as a rotational. body to cut the annular tooth forming channels I3 therein as more specifically shown in Fig. 3.

At this point in the process of manufacture, appropriate segments are out from the blade bowl to provide an integral multi-bladed web. In Fig. 4, the blade bowl I2 is shown with the outline of six blades and six intervening segments thereon, with one of the segments removed. The removed segment of Fig. 4 is indicated by the reference character I4 and, of course, has in its exterior surface the same tooth forming channels I3 cut therein when the segment I4 constituted a part of the bowl I2. The

segment I 4 or a similar segment cut from the bowl I2 is adapted to be cut up into smaller segments as indicated at I5 in Fig. 5, each segbladed web, more particularly shown in Fig. 6,

and which is held together at the central porof many uses in this form. It will be readil yappreciated that the teeth of the blades may be l sharpened, appropriately heat-treated, and pro; I

vided.with hard surfacing as desired before; or

after the integral multi-bladed web is vvelded to the rotating cutter body [0.

It has been found highly advantageous to pro- 1 vide the rotating cutter with supplemental bladesof less radial extent than the blades H. To achieve this result, the radially short bladesli, formed from a segment such as I4 cut from the blade bowl l2,'are welded to the rotating cutter body Ill as more particularly shown at I9 in Fig. '7. In this way, the finished rotating cutter, having alternating long and short radially extending blades, is produced with aminimum requirement of both material and labor.

It will be observed that the rotating cutter thus produced is especially well adapted. for usein drilling wells where a circulating .mud fluid is employed, since the cutter is provided withextensive open areas through which the circulating fluid 'rnay pass. To facilitate such flowof circulating fluid and minimize wear on the .central portionlfi of the rotating cutter, a stream-lined flow dividing member 28 may be welded on the upper side of the central portion [5 as shown in Fig. 7. I

The same method hereinabove described is equally applicable to the production of multibladed rotating cone cutters such as exemplified in Fig. 8. In this figure, the rotating cutter body 2| is cone-shaped rather than cylindrical. The

integral multi-bladed web 22 is, in this case, produced from a blade bowl having a conical interior surface rather than a cylindrical surface, such'as illustrated. for the blade bowl 12 in Fig.12. It will be appreciated that the same .steps are rials as rolled alloyed-steel without the necessity of expensive equipment and through the employment of procedure adapted to the use. of auto.- matic machines. I Additionally, I have provided performed in the same sequence in producing the 350 a method for producing a rotating cutter and a multi-bladed web which may be fitted accurately, ensuring a good weld and a rigid system of body, blades, and. teeth, equal in strength and performance to a cutter machined in one piece from a solid block of steel. The novel method of the instant invention enables the production of high quality rotating cutters with a saving of as much as in material and a like or greater saving in labor over, conventional i manufacturing meth ds. 4 :1 1' ,l

Having thus described my invention, what I claim is:

1. A method of manufacturing a rolling cutte rffor drilling-purposes comprising machining a cutter body for rotation on a shaft, machining as a rotational body a bowl to provide the same with an interior configuration conforming to the exterior configuration of said cutter body, cutting segments from said bowl to provide an integral multi-bladed web, and welding said multibladed webon said cutter body... i 2. A method of manufacturing a rollingcutter for drilling purposes comprising machining, a

cutter body for rotation on a shaft; machining as a rotational body a bowl to provide the same with .an interior configuration conforming; to thejex- V terior configuration, of said cutter body, cutting segments from said bowl to provide an integral multi-bladed web, welding said multi bladed web on said cutter body, cutting individual radially short blades from the said segments; and welding a'short blade to said cutter body intermediate the blades of said multi-bladed web. j-i

3. A method of manufacturing a rolling cutter for drilling purposes comprising ;m achining a cutter body for rotation on a shaft, machining as a rotational body a bowl to provide the same with an interior configuration conforming to the exterior configuration of said cutter bodyand with a plurality of annular toothforming. channels on the exterior thereof, cutting segments" from said bowl to provide an integral multi-bladed web, and welding saidmulti-bladed web on said a plurality of annular tooth-forming'fchanjnels on the exterior thereof, cutting segment from said 'bowl to provide, an integral multi -bladed web, welding said multi-bladed web on saidmli ter body, cutting individual'radially shortblades from the said segments, and welding ash'ortblade to said cutter body intermediate the"bladesjof said multi-bladed web. I 1 

